I shouldn't see why not. I sold my Adobe CS licence on eBay and just told them to transfer the licence keys to the new owner.

 

the licence keys are transferable between platforms. just contact adobe.

 

I thought that but on their website it says you can only do it with the most current version.

However, I would still contact them to ask.

 

Also, you can buy a license that works on both mac and pc, this article explains how:

http://prodesigntools.com/how-to-install-run-adobe-cs5-5-both-windows-pc-mac-os.html